Improvement in burglar-alarms



H. HOLC-ROFT.

BURGLAR-ALARM. No. 184,243 Patented N'ov.14,.1.876.

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TH E GRAPHIC ClLN-l'.

UNI ED STATES PATENT OFFICE.

HIS RIGHT TO JOHN D. WHITE,

0F SAME PLACE.

IMPROVEMENT IN BURGL AR-ALARMS Specification forming part of] Letters Patent No. 184,243, dated November 14, 1876; application filed April 24, 1876.

To all whom itmag concern Be it known that I, HENRY HOLOROFT, of Media, Delaware county, and State of Pennsylvania, have invented a new and useful Improvement 1n Burglar-Alarms,'which improvement is fully set forth in thefollowing specification, reference being had to the accompanying drawings.

The object of my invention is to construct an efficient and cheap portable burglar-alarm, that may be attached to the inside knob of a door-lock; and consists in a metal bell, the clapper of which is connected to a lever opperated by an escapement-wheel fixed to a cylinder, upon which is wound a cord, as will be hereinafter described by referring to the accompanying drawings, making a part of this specification.

Figure l is a front elevation of the bell, and arrangement for working the clapper. Fig. 2 is a side elevation of the same. Fig. 3 is a top view of the bell.

Similar letters in the drawings refer to like parts.

B is the alarm-bell, to which is fastened an upright, A. To this upright is fixed a stud, 12, upon which are fitted the esoapement-wheel d and drum S. The wheel and drum are connee-ted and revolve on the stud p; o is the escapement-lever or pendulum. The lower part passes through a slot, t, in the top of the bell, and forms the clapper. The escapementlevcr c is hung on a stud, g, at the top of the upright A. A part of the stud g is used as a guide for the cord f. K is ened to the upright A. 'On this arm is a guide, 1'. h is a small ring fastened to one end of the cord f. The other end of the cord is fastened to the drum S.

a round arm fast- The operation of my alarm is as follows: The cordfis wound on the drum S, as shown in Fig. 2. The end of the cord f is formed into a loop by putting it double through the ring h. This loop is slipped over the knob, and the cord is fastened by this loop to the spindle of the knob. The alarm is then hung on the knob by the arm K, care' being taken to have the cord f in the guides g and 7'. Should the knob on the outside of the door be turned in either direction, the alarm will fall off the knob. The end of the cord being fastened to the spindle, the weight of the alarm, in its descent, will cause the drum S to revolve, and with it the wheel 01. This wheel causes the escapementdever c to vibrate from right to left, and the hammer (shown by dotted lines) will strike the bell in rapid succession until the cord is unwound or the alarm reaches the floor of the room. The cord can be rewound and the alarm replaced on the knob, when it is ready for alarm, in case the knob is turned in an eii'ort to enter the room, as before described.

The invention may be connected to other parts or openings of the room, and should efforts be made to effect an entrance the alarm will be pulled off its support and the descent will give an alarm, as before described.

I claim A portable alarm, constructed with the clap per, connected to a lever which is operated by an escapement-wheel and cord when thrown from its support, as described.

H. HoLoRoFT.

Witnesses:

W. N. MARCUS, WM. F. ZIEGLEB.

giving another 

